Dust particle or outgasing can make a complete batch unusable. That's why some industries must work under "clean" conditions. But what does "clean" or "cleanliness suitability" mean and how can it be measured?
The cleanliness suitability is defined in the VDI guideline VDI 2083, sheet 9.1 “cleanroom technology – compatibility with required cleanliness and surface cleanliness”:
“Compatibility with the required cleanliness serves to assess pieces of equipment or air-handling components in view of their use in cleanrooms. It describes the generation or existence of the contamination generated by, or existing on, the piece of equipment or air-handling component.“ - VDI-guideline VDI 2083, sheet 9.1chapter 3.1.3
The best way to illustrate the purity is in contrast to another requirement, namely the cleanroom suitability. It describes the emission of contaminations of an operating material to the surrounding cleanroom. The cleanliness suitability is the particle delivery to the product being processed in the machine.
In short: the cleanliness suitability is inwards and the cleanroom suitability outwards.
Cleanroom suitability is part of cleanliness suitability and not really important for the actual process itself. Cleanroom suitability is only important if you want to know how many machines are allowed to work in a cleanroom, without affecting the classification and if cross-contamination must be prevented.
For measuring there are two different methods: The local measuring method and the holistic method. In case of the local measuring method, the air is measured at various points of the measuring object.
When using the holistic method the measured object is flushed with pure air in the exhaust air, the particle concentration is measured as in the local method. Additionally the volume flow of this air is determined. If the concentration of particles in particle per cubis meter is multiplied by the volume flow in cubic meters per second, a particle flow in particles per second is obtained.
P/s = P/m³ x m³/s
The cleanliness suitability is elementary for all, who use machines or components in a clean manufacturing environment.
The main suggestions for the application of cleanliness measures are:
Risk management, added value and return of investment are important keywords for each company. So if you ensure quality assurance along the entire process chain, smooth production processes, little rejects and only short downtimes are guaranteed. If machines, materials and components are suitable for cleanliness, numerous obstacles to clean, constant production are eliminated from the outset. Cleanliness suitability is a feature of quality, innovation and cost assurance.
If you want to know more about this topic you can read the blog post of COLANDIS or download the free whitepaper „Ways to ensure cleanliness suitability“ here.